RF signals such as cable television signals, cellular telephone signals, and even internet and other data signals, are often transmitted through coaxial cable to a subscriber. In particular, the RF signals are typically transmitted over long distances using trunk and distribution cable and drop cables are used as the final link in bringing the signals from the trunk and distribution cable to the subscriber. Trunk and distribution cable and drop cable both generally include a center conductor, a dielectric layer, an outer conductor and often a protective jacket to prevent moisture from entering the cable.
One problem associated with these coaxial cables is that moisture present in the cable can corrode the conductors thus negatively affecting the electrical and mechanical properties of the cable. In particular, during installation of the cable, moisture can enter the cable at the connectors. This moisture can also travel within the cable through the dielectric layer or along interfaces in the cable, e.g., between the dielectric layer and the outer conductor.
Several methods have been proposed to prevent moisture from entering the cable and being transported through the cable. For example, hydrophobic, adhesive compositions have been applied at interfaces in the cable to prevent moisture from moving along these interfaces. Flooding or water-blocking compositions have also been used at other locations in the cable to limit water transport in the cable. In addition, hydrophilic, moisture-absorbent materials have been used in cables to act as water-blocking materials. These hydrophilic materials not only water-block the cable but also remove moisture that is present in the cable.
Although these materials can provide adequate protection from moisture and can limit corrosion of the conductors in the cable, these materials have a tacky or greasy feel and thus are undesirable during the installation and connectorization of the cable, particularly when located on the outer conductor of the cable. As a result, these materials generally must be removed or otherwise addressed during installation and connectorization of the cable. Therefore, there is a need to provide a corrosion-inhibiting coating for cable that does not possess a tacky or greasy feel and thus that does not interfere with installation and connectorization of the cable.